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Nant y Bai Mill

A Grade II Listed Building in Llanfair-ar-y-bryn, Carmarthenshire

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Latitude: 52.0859 / 52°5'9"N

Longitude: -3.7909 / 3°47'27"W

OS Eastings: 277387

OS Northings: 244575

OS Grid: SN773445

Mapcode National: GBR Y4.BQBS

Mapcode Global: VH5DJ.7TRT

Plus Code: 9C4R36P5+9J

Entry Name: Nant y Bai Mill

Listing Date: 3 November 1997

Last Amended: 25 February 1999

Grade: II

Source: Cadw

Source ID: 19018

Building Class: Industrial

Location: At Nant-y-Bai, below and to the left of the road leading to Llyn Brianne.

County: Carmarthenshire

Town: Llandovery

Community: Llanfair-ar-y-bryn

Community: Llanfair-ar-y-Bryn

Locality: Nant-y-bai

Traditional County: Carmarthenshire

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The site is known from documentary sources to have medieval origins, as a grange to Strata Florida Abbey since at least 1202. There is a reference to a mill being on the site by 1512. Recent investigations of the dam wall to the rear of the mill building, suggest that it may incorporate medieval masonry, and the mill building itself clearly retains the remains of an earlier structure in the lower courses of its rear wall. These include some evidence for a previous siting of the water wheel, against the long wall rather than the present position against the gable. The mill building as it survives, however, is substantially C19, and the machinery also C19. It seems likely that an earlier building was largely rebuilt, and a house added to it in the C19, possibly altered in the later C19, as shown by the yellow brick window heads. Marked on the 1841 Tithe Map owned by Lord Cawdor, occupied by William Williams.


Mill and mill-house in a long single range, with the house (a 2 storeyed, 2-unit plan) to the right. Longer mill building to the left. Limewashed rubble throughout, with slate roofs. Mill has wide segmentally arched central doorway, with 4-pane fixed light windows to either side, and a secondary door to the right. Small opening to machinery bay to the lower left. Two 4-pane windows in upper floor. Overshot or high breastshot 16' (4.88m) wheel with cast-iron rim marked 'T.Bright, Carmarthen', against end gable. Rear wall is river boulder rubble, clearly of earlier construction in its lower courses; various small openings, including possible former axle hole for earlier wheel, and an oblique angled opening of uncertain original purpose.
House has two-storey, three-window range, much offset to left, of 8-pane sash windows, and C20 glazed door with overlight. Yellow brick heads to ground floor openings, timber lintels to upper windows. End stacks, that to left in brick and shared with the mill building to serve the corn-drying kiln within.


Mill is divided internally by 4 chamfered beams, with the left-hand bay partitioned off, and housing machinery. This appears to survive virtually complete, including iron pit wheel and spur wheel, together with all gearing. Cobbled floor. Large kiln in right hand corner, brick, with cast-iron lintel over fire box, and perforated tiles visible in the upper storey. 3 sets of wheels at first floor level, and remains of various chutes from the attic level. The roof trusses appear to be re-used and were probably retained from the earlier mill building in the C19 reconstruction: A-frame trusses, halfed and pinned at the apex and with a saddle; cut for collar beams, but these no longer extant. House retains original layout and some detail, including large principal fireplace.

Reasons for Listing

Listed as an integral water corn mill and millers house, especially notable for its early origins, and as containing a remarkably complete set of machinery, including a very well preserved corn-drying kiln.

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